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David Saxon
Lord Kelvin (1824 -?)
Location: University of Glasgow
Unveiled: 11 January 1999
Born in Belfast in 1824, William Thomson was the youngest (aged 10) and later the oldest (aged 75) student in the history of the University of Glasgow. In between he was for 53 years Professor of Natural Philosophy. He refused the Cavendish chair three times, made a fortune, became Baron Kelvin of Largs in 1892, and was the dominant scientific figure of his time. He and is buried in Westminster Abbey next to Isaac Newton. A nearby window pays tribute to him as “Engineer, Natural Philosopher.”
Yet today his achievements are unheralded and he is remembered mainly for his reactionary approach to the new Physics of the last decade of his life.
To appreciate Kelvin’s achievements, we must take ourselves back to 1841 when, at the age of 16, he published his first paper. This rescued a neglected work by Fourier, and showed that the instability of Fourier series close to sharp boundaries does not prevent their use to study the flow of heat. Thus the physics of continuous media was born. Kelvin took to heart Fourier’s message that one can describe in mathematics the behaviour of heat without knowing what heat is. Its relation to energy was as yet unclear and incompatible theories of ‘caloric’, to use the then current name, were in circulation. Kelvin first introduced the word ‘thermodynamics’ in 1848.
His creativity was by then reaching an astounding peak. 1849 saw papers by him on hydrodynamics, electricity, the heating and cooling of buildings by circulating air as well as the second law of thermodynamics. In 1850 he wrote on steam engines, geometry, electrolysis, the magnetic properties of crystals and regelation and produced a landmark paper on magnetism. This developed the whole field from two contrasting starting points, magnetic poles and current loops, introducing the vector fields B and H. He recast physics in terms of energy, being the first to write down the stored energies in an inductor and a capacitor, ½LI2 and ½CV2. Amongst the terms he introduced new into physics are: electrical capacity, energy, kinetic energy, absolute temperature, simple harmonic motion, magnetic permeability, magnetic susceptibility, stress over strain, bulk modulus, circulation, vorticity and vortex-sheet
Between 1858 and 1866 he laid the first transatlantic telegraph cable, an epic undertaking involving huge practical difficulties and a House of Lords enquiry. By 1866 the largest ship in the world (the ‘Great Eastern’) was able to carry the weight of cable needed. He also invented the inkjet printer (the ‘siphon recorder’) as the receiving and recording mechanism requiring the least signal power. (The only moving part is the ink.) The achievement of the transatlantic cable shrank the world more than anything before or since. It has the same logical structure as email – digitally encoded, packet switched, and seeking the least crowded route – and started the globalisation of information. Never again could a battle be fought, as in New Orleans in 1815, weeks after the peace treaty had been signed but before either General had been informed.
It earned Kelvin his knighthood and set him on a path to fame and wealth. Perhaps his most famous invention was the compass for iron ships, overcoming the ship’s permanent magnetism and the additional magnetism induced in the hull by the earth’s field. He worked over twenty years to refine the accuracy of units of electrical measurement, defining the ampere, volt, ohm etc as we know them today. He pioneered electric light: in 1881 his Glasgow home at no 11, Professors Square, became the first house in the world to be fully lit by electric lamps. He introduced undergraduate laboratories: previously students were normally just spectators at lecture demonstrations. Students flocked to work with him: Phillips came from Eindhoven to learn about electric light and students from Japan matched the flow of Glasgow academics the other way.
Kelvin believed passionately in the importance of being quantitative, saying “to measure is to know,” and “if you cannot measure it, you cannot improve it.” He was the first to calculate the ages of the earth and of the sun, by considering all known energy sources for the sun and how long the earth’s mountains could survive erosion. Knowing about neither radioactivity in the earth’s core nor nuclear fusion which powers the sun, his results were huge underestimates, causing uproar amongst evolutionists. His approach was both new and correct - but crucially incomplete.
Nevertheless he adamantly asserted that he had the whole picture. Contrast his earlier attitude: “when you are face to face with a difficulty, you are up against a discovery.” He had led the development of physics for over fifty years but was unable to enter the promised land of twentieth-century discoveries. He could not grasp the importance of X-rays or radioactivity. Yet by then he regarded himself as a failure because he could describe but not explain such things as the relation of electricity to matter and the periodic table of the elements.
But his boundless energy had led to 661 scientific papers and 75 patents. Asked to pick one highlight, scientists might choose the absolute scale of temperature: members of the public might opt for the Atlantic telegraph cable.. “His work lives and will continue to live. To him it has been given to make history which will live so long as intelligent man survives on earth. As the years roll on our indebtedness to him increases.” (Russell, 1912).
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